1. Field of the Invention
The present invention relates to a lens barrel and an image pickup apparatus, and more particularly, to a lens barrel and an image pickup apparatus disposed in a film camera, a digital camera, and the like.
2. Description of the Related Art
Conventionally, a film camera using silver halide film has been prevalent. Further, a digital camera capable of capturing image data into a memory without using a film has become popular rapidly in recent years. Any of the film camera and the digital camera generally includes a shutter and a diaphragm necessary for adjusting light quantity at the time of photographing. It is normally desirable that around the blades of the shutter and the diaphragm, other members are arranged with a fixed clearance so as not to be in contact with the blades of the shutter and the diaphragm. Further, in recent years, the cameras have been desired to be further miniaturized or reduced in thickness in order to improve the portability thereof. Thus, there occurs a situation where the other members are inevitably arranged even in the vicinity of the shutter and the diaphragm.
Further, in the camera described in Japanese Laid-Open Patent Publication (Kokai) No. 2004-347615, when photographing is not performed, the shutter and the diaphragm are retreated from a photographing optical axis, so that a lens and a part of a lens holder on the periphery of the lens are inserted in the opening formed by retreating the shutter and the diaphragm. This is to reduce the thickness of the photographing lens barrel.
However, in the above described cameras, the lens and the part of the lens holder on the periphery of the lens are inserted into the opening obtained by retreating the shutter and the diaphragm, and hence harmful light may be irradiated to an image pickup device. In particular, the period in which the camera is set in a non-image-pickup state is often overwhelmingly longer than the period in which the camera is set in a photographing state. In the long non-image-pickup state, the image pickup device may often be continuously irradiated with harmful light for a long period of time, which may cause destruction or performance deterioration of the image pickup device.